#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>      
#include <string.h>
#include <assert.h>

char* my_strcat(char* dest,const char* src)
{
	char* ret = dest;
	assert(dest && src);
	while (*dest)
	{
		dest++;
	}
	while (*dest = *src)
	{
		dest++;
		src++;
	}
	return ret;
}

int main()
{
	char arr1[20] = "accefg";
	char arr2[] = "abcefg";
	char* ret = my_strcat(arr1, arr2);
	printf("%s", ret);
	return 0;
}